GeoSnaps - Image of the Day
Geologic snapshots capturing Arizona’s geologic setting and mining history with a picture of the day from 1 January through 31 December 2013.
Check out previous GeoSnaps/Images of the Day.

Far to the west of the main visitor area, the Grand Canyon displays evidence for relatively recent basaltic volcanism. Here, at about River Mile 187 (downstream from Lees Ferry), a cascade of basalt is frozen in a side drainage to the Colorado River. The flow appears top be partially eroded since it was emplaced. Recent reediting of the basalt shows that volcanism commenced here about 830,000 years ago. (Photo by Wayne Ranney)